Prime Minister Saad Hariri’s abrupt resignation over the weekend was bizarre even by the often twisted standards of Lebanese politics.

He made the surprise announcement from the Saudi capital in a pre-recorded message on a Saudi-owned TV station.

Stunned Lebanese are convinced Saudi Arabia, Hariri’s long-time ally, forced him to step down to effectively wreck the prime minister’s delicate compromise government with the Iran-backed Hezbollah group.

In doing so, the kingdom throws Lebanon into potential turmoil, forcing the small nation to become a new front in the regional fight for supremacy between Saudi Arabia and Iran. The move comes at a time when Iran and its allies are seen to have won the proxy war against some of the Saudi-backed forces in neighbouring Syria.

Sunni-led Saudi Arabia, under Crown Prince Mohammed bin Salman, has been intensifying its confrontation with Shia powerhouse Iran. The two camps support rival sides in countries across the region, worsening conflicts in Yemen, Syria and elsewhere.

Each also has its proxies in Lebanon, but in recent years, Lebanese parties have intently tried - largely successfully - to prevent those tensions from blowing up into full-scale violence in a country still haunted by memories from its own 1975-1990 civil war.

Shia Hezbollah dominates Lebanon, but it has sought not to provoke the Sunni community, which in turn has avoided crossing the armed group.

The fear among some Lebanese now is that Saudi Arabia will upset that balance, trying to compensate for its losses in proxy wars elsewhere.

In Syria, Hezbollah and other Iranian-backed fighters allied with the Syrian regime have recaptured large areas and are working to take a much-prized land corridor stretching from Tehran to the Mediterranean through Iraq, Syria and Lebanon. By contrast, Saudi Arabia has been stuck in a fruitless war in Yemen against Iranian-backed Shia rebels, and a Saudi bid to isolate Qatar has failed to achieve its goals.

Saudi fingerprints were seen all over Hariri’s resignation on Saturday.

Hariri appeared on Saudi-owned Al-Arabiya TV in a recorded video from an undisclosed location, haltingly delivering a statement in which he accused Iran of meddling in Arab affairs and the Iran-backed Hezbollah of holding Lebanon hostage.

"Iran’s arms in the region will be cut off," he said, adding that he felt compelled to resign and that his life was endangered.